In recent years, mobile phones so called smart phones having a capability for sending and receiving voice, text and digital data become a main stream of personal communication devices. Also, a GPS (Global Positioning System) becomes a standard device to be installed in the vehicles.
However, in the case of mobile phone systems using radio communication technologies, still there are lots of areas which cannot be covered by the mobile phone service areas, particularly, in deep mountain areas and desert areas having less population not only in North America, but also in European countries and Asian countries.
Accordingly, emergency communication systems or devices for transmitting and receiving information via radio wave which can be used in these areas which cannot be covered by mobile phone serves are required. In order to establish communications between these emergency communication devices in a vehicle involving an emergency event and vehicles passing by the vehicle involving the emergency event, high speed communication protocol is required particularly when establishing communication between communication devices having relatively short communication distance, such as Wi-Fi® or Wi-Fi-Direct® or the like.